(function a() {
    console.log("立即执行")
})();



function x(i) {

    return function () {
        i += 2;
    }
}
var menu = function (num) {
    num = x(3);
    return num;
}
console.log(menu)

function z() {

}
console.log(z.prototype);
console.log(z.arguments);
console.log(z.caller);
console.log(z.length);
console.log(z.name);


function start(a, b, c) {
    return c(a * b);
}

var pro = start(2, 3,
    function (sum) {
        return sum + 2;
    })

console.log(pro)